Can we applied for spouse visa to US if we are married in between k1 fiance case and now that case is terminated by uscis.?

Yes you can apply for an immigrant visa through consular processing at this stage. Consult with an attorney for guidance.

Can i come back to home country after filing for greencard if i marry a US citizen in US?

That should not be your intention - to enter the US and marry a USC. You could travel after obtaining a travel permit but it is advisable to...

Yes the correct I765 category is C9. Refer to the instructions for further guidance.

What should i do?

Administrative processing can be a myriad of reasons, so it is best to contact the embassy directly to inquire if additional information is needed....

Yes you can adjust status despite any visa overstay as long as this was not his intent upon entry and he is married to a USC in good faith. It is...

How much to have an attorney to review all my forms before I file them? [Marriage based green card]

You can use the attorney search tool on Avvo to find an attorney and inquire directly about review options. Good luck.

No you cannot but your sister can once she becomes a USC (however the wait time is 12-14 years for siblings of USC). She can alternatively visit by...

Can you apply for visitor visa instead of applying for SB-1 visa?

Yes she can apply for a visitor visa and withdraw the SB1 petition. Consult with an attorney for guidance.

What i have to write in MY ds260 for my father name?

You should be consistent with how you previously indicated your father’s name, likely as on your birth certificate.

Do I have to pay the filing fee of 410$ for an Adjustment of Status category(c09) if I already paid 1225$ for my I-485?

Yes the I485 Fee is separate and is $1225. Review the instructions for guidance.